Turbine stator structure



United States Patent [72] Inventor Frank J. Gagliardi Paschall, Pennsylvania [21] Appl. No. 745,535 [22] Filed July 17, 1968 [45] Patented Nov. 24,1970 [73] Assignee Westinghouse Electric Corporation Pittsburgh, Pennsylvania a corporation of Pennsylvania [54] TURBINE STATOR STRUCTURE 2 Claims, 5 Drawing Figs.

[52] U.S.Cl 415/136, 415/139 [51] Int. Cl F0ld 9/04, FOld 11/00 [50] Field of Search 253/78, 788, 78D, 77.3, 39A, 39C; 103/1 1 1(c4); 23l/132(S);415/l36, 139

[56] References Cited UNITED STATES PATENTS 2,859,934 11/1958 l-lalford etal 253/78(B)UX Primary Examiner-Everette A. Powell, Jr. Attorneys-A. T. Stratton, F. P, Lyle and F. Cristiano, Jr.

ABSTRACT: In a turbine stator structure a blade ring supports diaphragm assemblies including a plurality of vane segments disposed between rows of rotor blades, and a plurality of rows of ring segments which encircle the rotor blades. The blade ring is divided into two semicircular halves with each half supporting a plurality of rows of vane segments as well as the rows of ring segments. Axial and radial seal members at the joints between segments are so constructed that the radial members retain the axial members in position and the radial members are retained by the axial members and the blade ring.

Sheet l of 2 wnmsssss' INVENTOR W W Frank J. Gugliurdi Patented Nov. 24, 1970 Sheet S 6 R 3 2. 8 w E 3 2 O W R O R v 8 m 2 mm. 2 W O R s 2 W B 4 O 2 3 R m Mm 5 mm F I l TURBINE STATOR STRUCTURE BACKGROUND or THE INVENTION expansion effects. Each diaphragm vane segment has an inner arcuate shroud segment and an outerarcuate shroud segment between which the stationary vanes or blades are secured. The

outer arcuate shroud segments and the ring segments are assembled in a blade ring divided into two semicircular halves. It is desirable to provide seals at the joints between the segments to minimize leakage of the elastic fluid through the joints.

ln acopending application Ser. No. 73l,l5l filed May 22, I968, now U.S. Pat. No. 3,5l9,'366 by R. F. Campbell and assigned to the same assignce as this invention there is described a seal arrangement particularly suitable for use at the joints between the inner shroud scgments'of the diaphragm structure. I

An object ofthis invention isto provide axial and radial seal members suitable for use at the joints between arcuate segmentswhich are assembled in the blade ring of the stator structure.

Another object of the invention is to so interlock the axial and the radial seal members that the radial members retain the axial members in position and the radial members are retained by the axial members and the blade ringwhen the. segments are assembled in the blade ring.

Other objects of the invention will be explained 'fully hereinafter or will be apparent to those skilled in the art.

SUMMARY OF THE INVENTION scgments are assembled in the blade ring.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying,

drawings, in which:

FIG. 1 is an'end view of the upper half of a turbine blade ring assembly embodying principal features of the invention, portions-being cutaway for clearness;

FIG. 2 is a sectional view of the blade ring assembly, taken along line lI-II ofFlG. I; t

FIG. 3 is an enlarged isometric fragmentary view, showing the end of one ring segment and the'manner of retaining the seal members in'grooves inthe ring segment;

FIG. 4 is a view, in plan, of one of the axially extending seal members utilized in the seal ring assembly; and

FIG. 5 is a view, in side elevation, of one of the radially extending seal members utilized in the'seal ring assembly.

DESCRIPTION OF PREFERRED EMBODIMENT I Referring to the drawings. particularly to FIGS. 1 and 2. the. structure shown therein comprises an inner tubularcasing usually called a blade ring 12'which supports a plurality of diaphragm assemblies 14, each containing an annular array of vanes or blades 16 which encircle a turbine rotor (not shown) that rotates about the central axis A of the turbine. In a multistage axial flow turbine. a stationary diaphragm assembly containing stationary vanes or blades is provided between rows of rotor blades which rotate with the rotor. The stationary blades of the diaphragm direct the tlow of motive fluid past the rotor blades (not shown) to motivate the rotor in a manner well known in the art. The blade ring 12 is divided into two semicircular halves, only the upper half being shown in the present drawing. The lower halt is similar in structure to the upper half. The two halves are secured together in any suitable manner, well known in the art. The blade ring 12 is mounted inside an outer turbine casing or cylinder (not shown).

As shown more clearly in FIG. 1, each diaphragm assembly 14 is divided into a plurality of arcuate segments 22 disposed in closely spaced relation with each other in an annular array. Each segment 22 has an outer arcuate shroud segment 24 and an inner arcuate shroud segment 26 between which the blades 16 are secured.

As shown more clearly in FIG. 2, the outer shroud segments 24 are generally channel-shaped in cross section, with axially extending tongues 28 provided inop posite sides of the channel which are received in circumfereutially extending grooves 30 in the blade ring '12, thereby slidably attaching the outer shroudsegments 24 to the blade ring. As also shown in FIG. 2,

. ring segments 32 are disposed between the shroud segments 24v to jointly define the outer periphery of the motive fluid passageway G. The ring segments 32 are attached to the blade ring 12 in a manner similar to the manner in which the shroud segments 24 are attached.

Each row ofring segments 32 encircles a row of rotor blades (notshown). In the present instancethrec annular rows l-R, 2R and 3-R ofarcuate ring segments and three rows l-S, 2-S and 3-8 of arcuate vane segments are shown. The segments 24 of rows 2-5 and 3-5 and the segments 32 of rows 2-R and3R are so shaped that the circles formed by successive rows of I segments increase in diameter. The inner shroud segments 26 of rows 2-8 and 3-5 are provided with inwardly extending flanges 34 which cooperate with seal members (not shown) and the rotor to minimize leakage ofimotive. fluid.

In orderto minimize leakage of the motive elastic fluid through the joints between neighboring arcuate segments, it is desirable to provide seals at the joints between the segments. In the aforesaid copending application there is described a seal arrangement particularly suitable for use at the joints between the inner shroud segments 26 of the diaphragm structure.

'The present application is directed to a seal arrangement particularly suitable for use at the joints between the arcuate ring segments 32' However, the seal arrangement herein described also may be utilized at the joints between the outer shroud segments 24 ofthe diaphragm structure.

As shown more clearly in FIG.;3, an axially extending seal member 42 and a radially extending seal member 44 are provided at each joint between neighboring ring segments 32. Each end of each segment 32 has a groove 46 therein for receiving the seal member 42 anda groove 48 therein for receiving the seal member 44. The grooves 46 and 48 intersect each other.

the gap between a pair of neighboring ring'segments 32 and is received in their associated grooves 46. The radial, seal member 44 extends radially across the gap between neighboring ring segments 32 and is received in their associated grooves 48 in the neighboring ends of the segments. The axially extending seal members prevent radial outward leakage of I elastic fluid and the radially extending seal members prevent axial leakage flow of the elastic fluid.

As shown more clearly in FIG. 3, the axial seal member 42 is retained in position in the groove 46 by the tab 52 on the radial seal member 44 which extends into the notch 50in the axial seal member 42; The radial seal member 44 is retained in the groove 48 by prick punching" 54 on the edges of the groove 48. A relatively small clearance is provided in the grooves 46 and 48 for the seal members 42 and 44, respectively. The prick punching is required to hold the strips in place during assembly only. After the parts are assembled in the blade ring 12, the seal strips are mutually retained. The tab 52 of the radial seal 44 extends into the notch 50 in the axial seal 42, thereby retaining the axial seal in position. The radial seal 44 is then prevented from falling out by the axial seal in one direction and the blade ring 12 in the other direction as shown in FIG. 3.

As explained hereinbefore, the seal arrangement herein described is particularly suitable for use at the joints between ring segments of a stator structure which has a relatively small differential in radial expansion and requires no rotation ofthe seal strip for assembly or circumferential expansion. The present arrangement may also be utilized at the joints between the outer shroud segments of the diaphragm structure of a turbine stator.

From the foregoing description it is apparent that the invention provides an interlocked sealing'arrangement for the gaps at the joints between arcuate segments of a turbine stator structure. The seal arrangement is particularly suitable for use with gas turbines and is effective to reduce leakage from the flow path and to obtain a reduction in the amount of hot gas leaking into cooled areas Since numerous changes may be made in the above described construction and different embodiments of the invention may bemade without departing from the spirit and scope thereof, it is intended that all subject matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

lclaim:

1. In an elastic fluid machine, in combination:

a blade ring;

a plurality of arcuate segments assembled in said blade ring and disposed in closely spaced relation with each other in an annular array thereby forming gaps between neighboring segments;

separate axially and radially extending seal members disposed between neighboring segments and extending across said gaps; 4

the ends of neighboring segments being provided with at least one groove for receiving an axial seal member and at least another groove for receiving a radial seal member;

said grooves intersecting each other;

each seal member being an elongated substantially flat metal strip;

the axial seal member having a notch therein; and

the radial seal member having a projecting tab on one end which extends into the notch and is effective to form an interlock therewith, whereby the radial seal member retains the axial seal member in position and the radial seal member is retained by the axial seal member and the blade ring'after the segments are assembled in the blade ring.

2 In an elastic fluid machine. in combination:

' a blade ring; r

gaps; 1 said seal members being so constructed that the radial members retain the axial members'in position and the radial members are retained by the axial members and the blade ring after the segments arc-assembled in the blade ring;

the ends of neighboring segments being provided with at least one groove for receiving an axial seal member and at least another groove-for receiving a radial seal member;

each seal member being an elongated substantially flat metal strip;

the axial seal member having a notch therein;

the radial seal member having a projecting tab on one end which extends into the notch and is effective to form an interlock therewith; and

prick punches on an edge of the groove containing the radial seal member for retaining the radial seal member in its groove in said segment during assembling of the segment in the blade ring. 

